b. August 1, 1820, in Troy, Illinois; d. April 13, 1895, in Springfield, Illinois. Herndon came to Sangamon County with his family (including his brother William H. Herndon) in 1821. Herndon read law in Springfield and was admitted to the bar in the winter of 1842-43. He served as the city attorney for Springfield, the attorney for Sangamon County, and the United States Attorney for the Southern District of Illinois. In 1858, he was appointed Disbursing Agent by the general government for Illinois. While his brother William Herndon was active in Whig and later Republican politics, Herndon was an active Democrat and edited the Illinois State Democrat newspaper from 1857 to 1860. In 1860, Herndon supported John C. Breckinridge for president, and during the Civil War, he was actively part of the anti-war effort. With the exception of an interval from 1868-1873, Herndon practiced law until his retirement in 1878.